


Make me Yours

by DarkxKitsune



Category: Teenage Mutant Ninja Turtles - All Media Types
Genre: Bottom Michelangelo (TMNT), F/M, Female Michelangelo (TMNT), Genderbending, Genderswap, M/M, Manipulation, Mates, Mating Cycles/In Heat, Michelangelo - Freeform, Mutation, Rough Sex, Vaginal Sex, tcest
Language: English
Status: Completed
Published: 2020-05-10
Updated: 2020-06-12
Packaged: 2021-03-02 21:55:56
Rating: Explicit
Warnings: Underage
Chapters: 3
Words: 8,991
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24113899
Author URL: https://archiveofourown.org/users/DarkxKitsune/pseuds/DarkxKitsune
Summary: Mikey is caught in a mutagen trap, his brothers don't get to him in time, yet, he seems completely fine. At least until they get home.Female Mikey!
Relationships: Donatello/Leonardo/Michelangelo (TMNT), Donatello/Leonardo/Michelangelo/Raphael (TMNT), Donatello/Michelangelo (TMNT), Donatello/Michelangelo/Raphael (TMNT), Leonardo/Michelangelo (TMNT), Leonardo/Raphael/Michelangelo (TMNT), Michelangelo/Raphael (TMNT)
Comments: 26
Kudos: 136





	1. Chapter 1

Leo’s heart was beating faster as he ran into the room, Mikey’s screams for help pushing him, and their brothers to run faster. They weren't going to make it, Leo knew that, and yet he still had to try. The fear of the unknown, images of horrible monsters that had been created from being exposed to raw mutagen had Leo screaming as he burst through the door, hoping that wasn’t the fate that had befallen the youngest of them. 

His screams were drowned out by Mikey, the shriek filled the room as the container opened. All they could do was stand there and watch in horror as the green liquid was poured over their baby brother. 

“Mikey!” Leo could year Raph yelling from somewhere beside him, being held back by Donnie as they all knew there was nothing that they could do now, whatever was going to happen, they would have to deal with it, face the consequences of being too slow to save him. 

Slowly the liquid drained away, the trap that Mikey was tied down to finishing its cycle as it sprayed water over him, washing off the remnants of the mutagen. 

Leo felt numb, he was too afraid to look properly, too afraid to approach and see the mangled mess his brother was likely to be. 

Donnie was the first of them to step forward, once the mutagen had been washed away and it was safe. 

“Mikey?” Donnie asked, reaching out gently he helped Mikey into a sitting position. 

“What… what happened?” Mikey asked. Leo watched as Mikey started inspecting himself, looking just as confused as the rest of them from the lack of changes. 

“Ya didn’t change?” Raph asked, and Mikey looked himself over again. 

“I don’t think so?” he offered, allowing Donnie to help him off the table. 

“You don’t feel any differently?” Donnie questioned, also taking a moment to look the smaller turtle over in curious amazement. 

“I feel a bit shaky, but I think that’s dremillin,” Mikey said. 

“Adrenaline,” Donnie corrected easily, leading Mikey over to where Leo was standing. 

The blue banded turtle looked Mikey over as well, thinking that this was too good to be true, however as the younger turtle stood in front of him, Leo could find no faults. Despite being subjected to a mutagen shower, nothing had happened to his precious baby brother. 

“Mikey,” Leo breathed out, wrapping his arms around the smaller turtle, hugging him tightly, feeling his own nerves calming now. “Let’s go home.” he said. An order that no one objected to. 

\---------x

The drive home had been a tense one, as all of them were still on edge, half expecting Mikey to suddenly double over in pain, to experience some sort of delayed reaction to the mutagen. This of course didn’t keep Leo away from the younger turtle. Keeping his arm wrapped around him, touching his arm, legs, head, he couldn't seem to stop touching him, though Mikey wasn’t exactly complaining, the attention felt nice. 

Pulling into the garage, one by one they exited the battle shell. 

“I want you to go take a shower, Mikey,” Donnie said, stopping the orange banded turtle from getting too far ahead of them. 

“What, why?” Mikey demanded. 

“You might have deposits of mutagen on your skin, and despite the lack of mutation, it could still be dangerous, to you, and to us,” Donnie insisted. 

“If it were that dangerous, you would have told Leo to stop touching me the whole way home,” Mikey pointed out, pointing a finger at the leader. 

Leo smiled at him, while he agreed with Mikey, he knew it was likely a good idea for them all to shower. “Tell you what, Mikey, you go jump in the shower, and I’ll come keep you company, Donnie’s right, it's better for us all to be safe than sorry, so we’ll shower first, then Raph and Donnie can,” Leo said. 

Mikey seemed happier that he wasn’t the only one being made to go shower and nodded his head. “Race you there!” Mikey announced and ran off ahead. 

“Aren’t you going after him?” Donnie asked. 

“He can have a head start, I’ll help unload the battle shell first,” Leo stated, turning to help Donnie as Mikey practically dove into the elevator, hitting the button that would take him up. 

The doors closed and Mikey grinned to himself, rocking back on his heels as he waited for the elevator to bring him up. He knew he was going to win this ‘race’ but he didn’t care, as long as Leo did in fact come join him. 

He’d been enjoying the seemingly random affection his eldest brother had been giving him on the ride home. It wasn’t often that Leo gave into that side of himself, and showed any outward affection towards any of his brothers. 

Mikey didn’t mind though, he knew Leo was the leader, and that required a certain amount of decorum. But he wasn’t going to pass up any amount of affection his brother planned to give him. 

The elevator doors opened and Mikey hurried out, heading straight for the bathroom he slipped inside, already removing his gear and tossing it into one corner of the room to be dealt with later. 

Turning the shower on, Mikey hardly gave the water time to warm up before he was under the spray, letting out a long sigh as the water hit his sensitive skin. Mikey couldn’t ever remember anything feeling so wonderful on his skin before, and he just stood there, eyes closed, head turned up into the spray of the shower as the water washed over him. 

He hadn’t realized how warm he’d gotten. Or how sensitive his skin was, each droplet of water tickled as it rolled down his scalded skin. 

Mikey bit his lip, shifting from one foot to another, moaning when he felt a strange heat in his gut, and something slick between his legs. It was too thick and slippery to be water, and Mikey railed a hand down his plastron slowly, shuddering at the strange sensations coursing through his body. 

Slipping his hand between his legs, Mikey gasped when his finger touched his slit, where the wetness seemed to be coming from, slowly tracing the outline of his slit, Mikey couldn’t hold back the moan that escaped him, feeling something twitching, he didn’t know what prompted him to do it, just the overwhelming feeling of wanting something inside him, he slipped his finger passed his lit, pushing it deeper. 

He was dimly aware that he should have met some resistance, should have probably felt his hardening cock by now. But there was nothing, just an empty space, though as Mikey moved his finger further, he realized that that first thought wasn’t entirely true, his inner muscles were clenching at his finger, the same slickness that had been coating his inner thighs was now all over his finger, making it far too easy to pull it out and move it back in. 

Mikey leaned back against the shower wall, legs spreading to give himself more space to work. He was dimly aware of the fact that he should probably stop, scream for his brothers, but he found himself unable to move from his current spot, the heat in his gut building at a rapid pace, his finger moving faster, pushing in harder, filling that empty space over and over again. 

He needed more, wanted more, this wasn’t enough and Mikey’s body seemed to know it, he was burning up, he needed help. Letting out a high pitched whine, Mikey was surprised when he heard an answering rumble. 

Eyes snapping open, Mikey lifted his head, staring up into the deep blue eyes of Leo, his brother was standing there in front of him, watching him, and Mikey was unsure how long Leo had even been there. He didn’t say anything, didn’t stop moving his hand, working his finger deeper into himself, easing a second finger in to spread his slit wider, he chirped. 

Mikey was unsure what that sound was, or why he’d made it, but it seemed to be enough to spur Leo into action, the blue banded turtle suddenly moved forward, crushing his mouth against Mikey’s in a deep dominating kiss. One that Mikey accepted willingly, opening his mouth, he moaned loudly as Leo’s tongue invaded, sliding along his own tongue, coaxing it into moving with his. 

Mikey responded, slowly at first, before lifting his arms to wrap around Leo’s neck, tilting his head so that they had better access to devour each other’s mouths. 

There were no words, neither of the turtles seemed very keen on the idea of talking things out as they continued kissing, Leo’s hand moving down Mikey’s sides, his knee nestling between the younger turtle’s thighs, letting Mikey rub against him, grinding down leaving a slick patch as he worked himself up to new heights of pleasure. 

Mikey’s head was swimming, whether from lack of air, or the boiling heat in his gut he didn’t know, or care, he just didn’t want Leo to stop whatever it was he was doing. Pressing more firmly down against Leo’s legs, Mikey chirped, rocking his hips faster, harder, rubbing his slit right along the slick patch he was leaving on Leo’s leg. 

Leo didn’t seem to mind, in fact his hands had settled on Mikey’s hips, and were pulling him to move even faster, coaxing him towards something. And Mikey let him, breaking the kiss, he threw his head back, his head connecting with the wall behind him. He let out a strangled cry, his fingers clawing at Leo’s shoulders as his hips shuddered and stilled, it felt as if something had just burst, his insides were twitching, slick juices were leaking out over Leo’s leg and Mikey could only stand there, mouth hanging open as he rode out the intense pleasure. 

Mikey took a deep shuddering breath, his body slowly coming down from the sexual high, Leo was lowering them to the floor, and Mikey blinked up at him though blurred vision. He didn’t ask what Leo was doing, somewhere in the back of his mind he knew exactly what his brother wanted now, and Mikey lay there, legs spread open and allowed Leo to settle between them. 

He accepted the kiss, rough though it was, it held a promise of more mind blowing pleasure, and something more, though Mikey wasn’t sure what it was, he accepted it all. 

A deep rumbling churr escaped Leo, the blue banded turtle pulling back to stare down at Mikey. The younger turtle was splayed out before him, and Mikey was staring right back at him. It was almost as if they were having a silent conversation, and Leo was looking for something. 

The water beat down on both of them, they didn’t speak, just stared until finally Mikey chirped, tilting his head back, spreading his legs wider, lifting his hips as much as he could. 

Leo moved his hips forward then, and Mikey felt it for the first time, the hard bulge that was hiding Leo’s cock, Leo started grinding his slit against Mikey’s slick one, pulling a gasp from the younger turtle. 

“Oh…” Mikey breathed out, biting his lip, his body trembling with anticipation. His finger had felt amazing before, but it hadn’t been enough, feeling Leo grinding against him, Mikey knew now what his body was craving, what he needed, and he chirped again, lifting his hips eagerly. 

Leo churred, and Mikey felt his brother drop down, the hard flesh hitting Mikey’s plastron, sliding up along his slit as it did so. Leo’s breathing was ragged as he stared down at Mikey, slowly thrusting his hips now, dragging his cock along Mikey’s slit in slow agonizing movements. 

“Leo…” he breathed out, feeling like he should tell his brother something, felt like this might be their last chance to get a grip on their sanity. But as Leo pressed forward again, and Mikey felt the head of his cock slip inside, any possible hesitation Mikey had vanished. 

Mikey bit his lip, heart hammering in his chest as he was stretched further, Leo’s cock was a lot thicker than a couple of fingers, and the slight sting was boarding on hurt. Mikey tilted his head back again, breathing deeply as his body tried to accommodate Leo. 

Leo didn’t stop until his plastron was flush with Mikey’s, and he let out a huff of air. “I’m in,” he breathed out and Mikey blinked, staring up at Leo, only to see his brother was staring down between their bodies. Curious himself, Mikey lowered his own gaze, and gasped, cheeks burning as he saw, and felt, what Leo was talking about. His cock was buried in Mikey’s slit, and Mikey could feel every inch of it, his inner muscles clenching, and Leo moaned, his cock twitching. 

Mikey could feel the heat from before building again. He never thought being filled in such an area would feel so good, then again, he knew that until that morning at the very least his own cock had occupied the area Leo was now filling. The fact that it was missing was the furthest thing from Mikey’s mind at the moment. 

“Mine,” Leo breathed out, his eyes transfixed on Mikey as he pulled out slowly and thrust back inside. 

Mikey cried, his hands reaching up above him to press on the wall by his head, using that as leverage to hold himself still while Leo pulled out and thrust in again, rocking Mikey’s body harder this time. 

Mikey lifted his knees, hooking his feet onto the edge of Leo’s shell, exposing himself more, giving Leo a better angle to thrust at, an offer the blue banded turtle happily took. 

Churring loudly, the sound muffled by the water splashing down around them from the shower, the water only helping make things more intense as it hammered down on their skin, making each movement more slick as Leo gripped at Mikey, moving faster. 

Mikey couldn’t even begin to describe how it felt, having Leo’s thick cock filling him, his inner muscles gripping at the appendage, wanting to hold it inside him longer than Leo was allowing. Each time his brother pulled out Mikey felt empty, which pulled a needy whine from him before he was filled again. 

Each thrust forward seemed to push Leo deeper into him, hitting something deep inside that had Mikey rocking frantically into Leo’s thrusts. “More,” he breathed out desperately. 

Leo was more than happy to oblige. His hands moved from Mikey’s sides down to his ass, lifting it further off the floor, plunging his cock deeper into the warm, wet space. Churring and growling, his fingers dug into the skin of Mikey’s ass as he held him there. 

“Oh… oh god, Leo!” Mikey cried out at the new angle, feeling Leo’s cock hitting that spot harder, the heat in his gut seemed to be rapidly building as Leo assaulted his insides, his slick walls gripping and fluttering around him as he pushed to move faster. 

Mikey thought he’d heard something, but deemed it unimportant as Leo churred again, pulling a chirp from Mikey as he locked his feet around Leo’s shell, gripping his inner walls around the shaft. 

“What tha fuck!?” Raph’s exclamation had Mikey turning his attention to the door, not only was Raph standing there, but Donnie as well, and Mikey was sure it was the sounds that had drawn them in, or perhaps it was the smell. Either way, he didn’t really care as his attention was stolen by Leo again, his older brother growling, a warning for their other siblings to stay away. 

Mikey was okay with that, letting himself be swept away again by Leo, the sounds, the scent, the feeling of being filled, the cock twitching deep inside him as Leo started moving faster, thrusting harder, his plastron scraping against Mikey’s with each thrust, pushing all the way in and holding himself there long enough to grind his hips, before pulling out to repeat the action. 

Mikey chirped, gripping his legs tighter around Leo, the heat building even faster, knowing that Donnie and Raph were watching them, and Mikey could smell them, they weren’t unaffected by the secnt surrounding them, and though neither of them said anything else, they didn’t leave either, just stood there, watching as Leo continued fucking their baby brother. 

“Oh, ah-ha Leo, oh god, oh…. There… so… so good,” Mikey moaned, pressing the heels of his feet into Leo’s shell, pulling him deeper, clenching around the tick cock that was twitching and pulsing inside him. 

This new position forced Leo to rock his hips in a more grinding motion, trying to keep up the friction that was driving him wild, though he didn’t seem to complain about the fact that Mikey was holding him inside. 

Feeling the cock stirring up his insides, being held against that one spot that sent spikes of pleasure through him, the heat was so intense this time, building far past what Mikey thought he could handle. He was almost there, he could feel everything inside him start to coil tightly, his inner muscles gripping and milking Leo’s cock. 

Leo’s breath hitched, his whole body tense and Mikey threw his head back crying out as Leo’s cock suddenly twitched almost violently inside him, and Mikey felt the first rush of heat filling him. It was ecstasy, each twitch of Leo’s cock added to the heat as the blue banded turtle pumped his seed deep inside Mikey. 

Mikey wrapped his arms around Leo, pulling his legs tighter holding him inside as he felt the warmth filling him as he felt something snap, his insides twitching, his juices mixing with Leo’s seed. 

Mikey’s energy left him, slowly releasing Leo as he let his legs and arms fall back to the floor, his whole body felt like it was tingling, his insides still twitching as Leo pulled out slowly, the two of them coming back to their senses. 

Leo stared down at Mikey, the realization of what had just happened written all over his face. Mikey however, was feeling too tired to really care overly much, he felt satisfied, and let his eyes drift shut, intending to sleep in the afterglow of such mind blowing sex.


	2. Chapter 2

Mikey was sitting on a chair in Donnie’s lab, his cheeks were bright red as his three brothers kept their distance, standing over by Donnie’s computer as the purple banded turtle ran test after test. 

The only thing they knew for certain, after the last five hours of having blood drawn, and Donnie running test after test, was that Mikey was now somehow female. Though they hadn’t needed tests to figure that one out, as Mikey and and Leo had discovered this on their own. 

“So, what’s wrong with him?” Raph finally asked as Donnie typed away on his computer some more. 

Mikey frowned at hearing that. “There’s nothing wrong with me,” Mikey insisted, feeling hurt by Raph’s question. 

“You and Leo were just goin’ at it like fuckin’ rabbits in the shower!” Raph said. 

“And?” Mikey asked, smiling almost sweetly at his brother. “What’s wrong with that?” Mikey had the satisfaction of seeing Raph’s cheeks turn bright red, his mouth working but no sound was coming out. Mikey’s smile widened and he slipped from his chair. 

“Were you jealous that it wasn’t you in there? Pinning me to the shower floor-”

“Mikey, enough,” Donnie said, turning in his chair to glare at the orange banded turtle. “Sit back down and stay there.” he ordered, then turned to Raph. “And technically Mikey is right, there isn’t anything actually wrong with him,” 

“Then why is he actin’ like that!” Raph demanded, pointing towards Mikey who had sat back down, but was still eyeing Raph up and down like he was some sort of treat. 

“Because, Mikey’s in heat,” Donnie said flatly. 

“Wait… that can happen?” Leo asked and Donnie turned to look at him next. 

“Not normally, no, but considering Mikey’s been mutated again, it’s the only thing I could logically come up with.” Donnie said. “These tests aren’t showing much of anything, other than he had high hormone levels, and I won’t know for certain if my hypothesis is correct, until Mikey’s come down from this sexual high.” 

“And how long will that take?” Raph demanded, narrowing his eyes at Mikey when the other turtle shifted in his seat again. 

“I don’t know Raph, let me just pull out the calendar that I kept just in case something like this happened,” Donnie said flatly, and Mikey turned his attention towards him next, slowly licking his lips. 

“The only thing we can do is wait it out, and try to resist the new urges we’re going to feel, at a guess, something like this I don’t think should last more than a week,” Donnie said. 

“Right, so we just gotta stay away from Mikey for a week? How the fuck do we do that!?” Raph huffed. 

“We could lock him in his room,” Leo suggested. 

Mikey bit his lip, he didn’t like where this conversation was going. He honestly didn’t see what the big deal was about all this, or why his brothers wanted to avoid him all of a sudden, Leo hadn’t been too keen on avoiding him in the shower, and if Mikey remembered correctly, it had been Leo to make the first move. “Why do I have to be locked up?” Mikey asked, drawing the attention of the three male turtles, just having them look at him sent a quiver down his shell, and had his tail wagging almost excitedly. 

“It would only be for a few days, Mikey,” Donnie insisted. “We don’t know what kind of side effects your mutation is going to have,” 

“So I’m being punished, because Leo jumped me in the bathroom,” Mikey snapped. 

“That’s not what happened,” Leo defended, his own cheeks getting a red tint to them. 

“Oh, it’s totally what happened bro, I was washing up, and then you were on top of me, pinning me, sliding your-” 

“Enough!” Donnie interrupted. “It doesn’t matter who started it, the point is, we can’t let it happen again, so Mikey, I’m sorry, but you have to stay in your room until you’re back to normal,” Donnie said. 

Mikey stood up suddenly, narrowing his eyes at Donnie, then looked at the other two turtles. He knew he couldn’t fight his way out of this, and part of him knew that they were right, he still didn’t think it was fair though. “Fine,” he said, “might as well start now,” he snapped and stormed out of the lab. 

The three remaining turtles let out a collective sigh when they heard Mikey’s door slam shut, and the air already seemed to feel a bit lighter around them. 

“I think it would be best if we took it in shifts to bring Mikey his food, and maybe some comic books to keep him entertained,” Donnie suggested. “Because he’s right, locking him up isn’t fair,” 

“No, it’s not,” Leo agreed. “But there’s very little we can do about it, not if we can’t control ourselves around him,” he said, though if he were honest with himself, he really didn’t want to control himself, simply being reminded of how it felt to be on top of Mikey, to be sliding into that warm space between his legs. Leo took a deep breath and let it out slowly. “I’m going to the dojo, Donnie, maybe you take the first shift of keeping an eye on Mikey,” he suggested. 

“Good idea, I’ll go get the nerd some comics,” Raph said. “I know a good place that has a decent stash,” the red banded turtle said. 

“Maybe grab a pizza while you’re out, we’re going to have to live on takeout food for the next week, unless either of you fancies trying to cook,” Donnie powered his computer down and stood up. 

“Nah, I’m fine with takeout,” Raph said, grabbing a bag by the door as he headed out, as this was going to be a big haul of things, and would need his hands free. 

One by one they left Donnie’s lab, Raph leaving the lair, Leo heading to the dojo, and Donnie went to the kitchen, fixing Mikey a snack before taking it to his room. He tapped on the door before pushing it open slightly. 

“Mikey?” he said, pushing the door open a bit more and frowned, seeing Mikey splayed out on his bed, one leg hanging off the side, the other bent up, putting everything on display and Donnie swallowed. “What are you doing?” he asked. 

“I’m resting, counting the cracks on my ceiling,” Mikey said flatly, lifting his head to look at Donnie, then looked down to where Donnie’s eyes were fixed. “Why, see something you like?” he asked, spreading his legs wider and Donnie swallowed. 

“Not really, no,” he lied, bringing the snack further in and setting it down on Mikey’s bedside table. “I know this is hard for you, I really do, and I do agree it’s not fair, but Mikey, we don’t know what kind of side effects this has, we’ve never had to deal with anything like this,” Donnie tried to explain. 

“So, if there’s no side effects, I can come out of my room and I don’t have to do this again?” Mikey asked, sitting up a bit straighter. 

Donnie nodded his head. “Exactly,” he smiled, reaching out to touch Mikey’s cheek, but stopped himself, pulling his hand back quickly. Mikey reached out and took Donnie’s hand though, bringing it to his face, making Donnie cup his cheek. 

“I’m not contagious, bro,” Mikey smiled almost sadly at Donnie. 

“I… I never thought you were,” Donnie said, breathing in deeply. 

“Then tell me, please, why I can’t just be with you… and Leo, and Raph,” Mikey said, nuzzling against Donnie’s hand, turning his head slightly to kiss Donnie’s wrist. 

Donnie took a shuddering breath, his hand twitched, knowing he should pull it away, but Mikey held it, lifting his eyes and locking them with Donnie’s. “We don’t know what could happen,” 

“That’s not what you’re worried about,” Mikey accused. “If you were that worried, you would have tested Leo too,” Mikey pointed out, and Donnie’s eyes widened, no one else had caught on to the fact that Donnie hadn’t taken any blood samples from Leo, or at least he had thought no one had noticed. 

“You’re hiding something,” Mikey shifted closer to the edge of the bed, and Donnie bit his lip, his eyes darting down as Mikey spread his legs open a bit more. 

“I… I’m not,” Donnie argued, swallowing hard. 

“You’re a bad liar,” Mikey accused, shifting closer still, until he was sat right on the edge of the bed, Donnie’s knees between his legs. “It’s my body, I was the one who was mutated, I have a right to know what could happen, why you don’t want me to lay down right now, spread my legs open for you, just like I did for Leo,” Mikey said. 

Donnie couldn’t hold back the moan at the mental picture Mikey was painting for him. He stood up from his chair suddenly, the only thing stopping him from bolting to the door was the grip Mikey still had on his arm. With a sudden jerk, Donnie was tumbling forward, and Mikey was falling back, his legs spread apart to accommodate Donnie’s body between them, and the purple banded turtle was trapped, his lower body flush with Mikey’s, and his eyes locked with baby blue ones. 

“Leo felt so good, deep inside me, I want to feel you too, Donnie, don’t you want it?” Mikey asked, lifting his hips, slowly grinding his pelvis against Donnie’s lower plastron. “I want you to stretch me, I want-” whatever else Mikey wanted was cut off as Donnie crushed his lips against his. 

Donnie knew he had limited self control, knew that the second he walked in the room and saw Mikey laying on the bed, that this was likely going to be the outcome, and loathe as he was to admit it, Donnie had been hoping that this would happen. He wasn’t jealous that Leo got Mikey first, and logically he knew that giving in was a bad idea, but there was something so enticing about Mikey now, the scent he was giving off. 

Donnie had been sure that he could logic his way out of a situation like this, that he was smart enough to not be trapped and drawn in by such a mundane thing such as hormones. But he had greatly overestimated his abilities, and right now, he really couldn’t give a damn. 

Mikey was trapped under him, the smaller turtle letting out a needy whine as he ground his hips upwards, begging Donnie with his body, and Donnie’s own body was only more than happy to reply, roughly grinding his hips forward, rubbing his growing bulge over Mikey’s slit. 

He kept kissing Mikey, forcing his tongue into the willing mouth, pulling a chirp from the turtle trapped under him, that sound alone when straight to his cock, and Donnie felt it throb almost painfully in his plastron. Breaking the kiss with a gasp, Donnie sat back, letting his cock drop down, the appendage hitting Mikey’s lower plastron as it did so. 

“Oh!” Mikey gasped, lifting his hips, rubbing against the hard flesh. Placing a hand on Mikey’s abdomen, Donnie pushed him down onto the bed. 

“No, you want this, but I’m in control,” Donnie’s voice was rough, and he felt Mikey shudder under him. “And I have some rules,” he said firmly, causing Mikey to whine. 

“Rules later, fuck me now!” Mikey demanded, trying to lift his hips again. 

Donnie resisted to give in to the demand, pressing more firmly down on Mikey. “No, you listen, or I get up and walk out right now,” he said, though he didn’t know if he had the strength to do that, but that wasn’t something Mikey needed to know. 

“No! No stay!” Mikey grabbed Donnie’s arm, holding onto him, his legs lifting to wrap around Donnie’s shell. “I’ll listen, rules, just, please, make it quick, I feel hot, so, so hot,” Mikey breathed out. 

Donnie licked his lips and nodded. “Rule one, I’m in charge, we go at my pace,” he ordered and Mikey nodded, seemingly okay with that order. “Rule two, you are in heat, and we don’t know what that means in full detail, so… I won’t be finishing inside you,” he said. 

Mikey whined, but nodded his head again. “Is that all?” he asked. 

“If you break these two rules, I reserve the right to tie you to the bed, and fuck you to my hearts content,” Donnie said and was surprised to hear Mikey moan at that, tilting his head back, it was such an accepting and submissive pose that Donnie couldn’t hold himself back any more, leaning over Mikey he bit down on his neck, sucking and nipping as he left a vivid mark, right next to the one Leo had left before. 

Mikey tilted his head to the side, giving Donnie more space to work, biting his lip as the purple banded turtle shifted forward, his cock rubbing against Mikey’s slit now. 

Donnie pushed himself back up, reaching one hand between their bodies he grabbed his own cock and lined it up against Mikey, rubbing the tip along his slit, feeling how wet Mikey was already. Pushing his hips forward, he churred as the head of his cock was easily pulled inside, he wondered if Mikey had been this tight for Leo, or if this was after he’d been loosened up. 

Donnie decided he didn’t care though, as Mikey’s inner walls gripped his cock, surrounding it as he pushed himself deeper. 

Mikey chirped, tightening his legs around Donnie’s shell, trying to pull the turtle deeper, however stopped when he remembered that Donnie was supposed to be the one in charge, and might take this the wrong way. So Mikey lowered his legs back to the bed, and let Donnie slowly sink into him, let his cock stretch his slit until their plastrons met, and they both held still. 

Donnie tried to suppress the full body shudder, feeling his plastron flush against Mikey’s now, he’d managed to push his whole cock inside her, without any grimace of pain from her. He could feel the slick juices coating his cock now too, the inner muscles fluttering and clenching around him, as if trying to pull him even deeper. And Donnie found himself wishing he could give Mikey what he wanted. 

“Mikey,” Donnie breathed out, looking down at him, he pulled out the bare minimum before snapping his hips forward again, pulling a pleasured cry from Mikey. Pleased with the result, Donnie repeated the movement again, pulling out a little further each time, before snapping his hips forward, pushing his cock back inside. 

“Oh! Ah… Donnie, so, so good,” Mikey whined, mouth hanging open as he gripped at the bedsheets. 

Mikey’s obedience didn’t go unnoticed by Donnie, and he was impressed with how much Mikey was holding himself back from grabbing at him, letting Donnie move at his own pace. Donnie decided to test Mikey’s resolve, slowing down for a moment, he eased his cock out of the tight space, before pushing back in. 

It was a slow, almost agonizing pace, and Donnie’s cock twitched with the need to be buried deep in Mikey’s body once more. And it wasn’t until Donnie was easing cock out for a second time, that he realized he was treating Mikey like his own personal experiment, testing what he could do, and what results that would gain him. 

Mikey chirped, and moaned, pulling at the bedsheets, his legs twitching, lifting up to almost wrap around Donnie before being lowered to the bed again. “Oh god, oh god, Donnie, more, don’t tease, I need more, please!” Mikey practically sobbed. 

Donnie almost relented then, he wanted it too, wanted to pound into Mikey, thrust his cock into him over and over again until he came inside her, filling her like Leo had done only hours ago. Donnie reminded himself he couldn't do that though, and he was getting a sadistic kind of pleasure watching Mikey wrythe under him, wanting desperately to make Donnie move faster, but knowing if he did so, it would break Donnie’s rule. 

Donnie decided then that he wanted to force Mikey to break his rules, so as painful as it was to keep going so slowly, he kept it up, feeling the cool air hit his cock as he pulled out of Mikey, only to feel the wonderful warmth surrounding him again as he eased himself back in, pushing himself as deep as he could go, holding himself there before repeating the action again. 

Under him Mikey pulled and twisted the blankets, his head turning from side to side as he gasped and moaned, and Donnie could feel how much the younger turtle was trembling. Just a little more, he told himself, Mikey was almost there, almost ready to snap. What Donnie had not expected though was to feel the muscles suddenly tighten around his cock, and for Mikey to throw his head back, arching off the bed as a rush of warmth washed over Donnie’s cock, making Mikey’s hole slicker. 

“What…” Donnie started to ask, his eyes widening in realization. Mikey had just climaxed, his inner walls were still twitching and pulsing around Donnie’s cock. Donnie had made Mikey come. 

“Oh god, Mikey,” Donnie breathed out, suddenly lunging forward, slamming his cock back inside him, wrapping his arms around Mikey’s shoulders, covering the smaller turtle with his own body as he started to rut into him. The wet sounds his cock was making as it moved in and out of the dripping hole were lewd, yet more arousing than Donnie ever thought they could be. 

Mikey wrapped his own arms around and legs around Donnie, though didn’t constrict his movements, just held on as his body was rocked violently by Donnie’s quickened rough pace. Grunts and groans filled the room, the old mattress squeaking and shaking under them as Donnie worked his hips, forcing his cock deeper and deeper into the tight space. 

The only thing that mattered to Donnie in that moment was his own completion, he had to finish. 

“Donnie,” Mikey whined. 

“Almost, fuck, I’m almost… there, I’m… oh god damn, so good, Mikey, I’m cumming, fuck!” Donnie cursed, tring to pull back, remembering at the last second that he shouldn’t be finishing in Mikey. The smaller turtle stopped him though, tightening his legs around Donnie’s shell, locking them in place, and forcing Donnie’s cock deeper. 

“No, Mikey no, wait I can’t, oh fuck, oh fuck, here it comes, fuck!” Donnie clenched his eyes, his cock twitching and pulsing deep inside Mikey as he filled him. 

Mikey let out a long satisfied moan, his body trembling as he felt Donnie’s seed shooting up into his slit. It was such a satisfying feeling, and Mikey didn’t let Donnie go until he was sure his brother was finished, and only then did he let his legs slip back down to the bed, and let Donnie pull out. 

Shuddering, Donnie eased his cock out of Mikey, sat back on his knees and watched as Mikey’s juices and his seed started leaking out, dripping down onto his tail. 

Mikey smiled, trailing a finger down between his legs, gathering up the seed that had escaped, rubbing it and pushing it back inside, smiling at Donnie as he did this. 

Donnie couldn't stop him, couldn't even think to stop him, he honestly didn’t know how to. He did know one thing however. “This week is going to be impossible,” he sighed.

**Notes for the Chapter:**

> Two down! One to go! ^_^
> 
> I need suggestions! Positions, and places for these four to have sex.


	3. Chapter 3

**Notes for the Chapter:**

> Raph's turn! ^_^

The next few days were filled with high sexual tension as the three teenage boys did their best to avoid their younger brother turned female. 

It was something easier said than done, more than once Leo had found himself standing outside Mikey’s door, eyes glazed, cock hard and leaking. And Donnie was ashamed to say he had caught himself multiple times in one day leaving his lab and heading towards Mikey’s room with only one thing in mind. 

Raph, however, had intervened on each occasion. He woudln’t go as far to say he wasn’t affected by the delicious scent Mikey was letting off, the scent that begged for someone to fuck him, to fill him, to impregnant him. 

Raph suppressed a shudder, sadly for him, it wasn’t one of disgust. He knew he was the only one who hadn’t caved, the only one who was actually doing what he had been told, because they didn’t know what consequences would come of this. 

But Raph knew, he had dreamed about it, he’d been locking himself in the bathroom, fisting his cock, jerking off to the fantasy of what Mikey would look like, stomach rounded from being filled, from being fucked by him, forced to carry their children. 

The red banded turtle had never come so hard in his life, or so often. He didn’t like being the only one left out, but he cared about Mikey too much, cared about all his brothers too much, to let them continue with their dangerous actions, at least until Donnie could do some more tests and find out if it was actually safe. 

By the time the week was rolling to an end, Raph noticed that he was having to stop Leo and Donnie less and less, and the scent that had been so intoxicating was fading. It didn’t stop the dreams, it didn’t stop Raph’s furious solo sessions, but it helped him resist the temptation. 

Waking up near afternoon, Raph grimaced as he lifted his hand from his sticky chest. Last night had been one of the best, and worst nights for him, no sooner had he reached his climax had his cock been hard and ready to go again, he’d only fallen asleep out of pure exhaustion. 

Groaning Raph shifted himself from his bed and stretched, deciding that a shower was definitely in order, as no amount of tissues was going to clean this mess up. 

He made quick work of washing up, knowing he’d overslept, and he’d likely already missed his morning chances to stop Leo and or Donnie from sneaking into Mikey’s room. 

Making his way out into the living room, Raph stopped short when he saw Mikey sitting on the couch. His eyes darted back towards Mikey’s room, only noticing now that the door was open, he looked back at his younger brother and swallowed. 

“What are you doin’ out here?” he demanded. 

Mikey turned to look at him, smiling innocently. “Donnie let me out,” he stated. 

“I don’t believe ya, where’s Leo and Don?” Raph demanded, looking towards the lab. 

Mikey simply shrugged. “Dunno, haven’t seen them since breakfast,” he admitted, turning his attention back towards the TV. 

Raph knew Mikey must be lying, there was no way that Leo or Donnie would have left Mikey alone unsupervised, not with what was happening. Deciding to leave Mikey on the couch for now, Raph went first to the kitchen, looking inside he didn’t see either of his brothers, but the smell of sex was thick in the air. 

Growling Raph turned back around to glare at Mikey, he didn’t say anything just yet, storming his way to the lab next. 

“Donnie’s not in there,” Mikey said, and Raph ignored him, pushing the door open and looked inside, Mikey had been right, there was no sign of Donnie in there, or Leo. Which only really left the dojo, or their bedrooms. 

As Raph made his way across the lair once more, heading for the dojo, a soft hand stopped him. Jerking his arm away as if it had been burned, Raph turned fully to face Mikey, the smaller turtle was standing so close to him, and Raph hadn’t seen or heard him move from the couch at all. 

“They’re fine, Raphie,” Mikey practically purred. “We all had breakfast together, they likely went back to bed though, they were both really tired.”

“What,” Raph swallowed. “What did you do?” he demanded. 

“Do you want to know?” Mikey asked, leaning in closer and Raph caught a whiff of Mikey’s new scent. It really wasn’t as strong as it had been, but it had more of an affect on him, it felt as if it were more concentrated. 

Raph found himself nodding his head slowly, licking his lips as he looked down at Mikey. 

“Well, Donnie came to my room this morning, he’s been working so hard, so, so, hard,” Mikey stepped forward, and Raph found himself backing away, fighting his body's instincts to grab Mikey and have his way with him. But he was curious about what had happened while he had been sleeping. “He said I wasn’t in danger any more, that the mutagen has changed me with no… side effects,” 

“You’re a chick now!” Raph protested. “How is that not a side effect?” 

Mikey giggled. “Okay, not dangerous side effects then, he said I could come out of my room, but I wanted to thank him,” 

“So ya fucked him again?” Raph snapped. “Mikey, Don said ya can’t-”

“Oh, but he said I could, in fact, he begged me for it,” Mikey smirked. “He had me right there, against my bedroom wall, I was dripping by the time he was done, he filled me up so much,” Mikey bit his lip, moaning at the memory, and Raph nearly mirrored the noise as he pictured doing the same to Mikey, he held himself back though, staying just out of reach of his little brother. 

Raph knew he looked like a coward as he was practically running from Mikey as he kept advancing slowly on him. “And Leo?” Raph found himself asking, and Mikey’s smile widened. 

“Leo was in the kitchen, making tea,” Mikey admitted. “I didn’t have to ask him for anything, he was so rough, so wild, pinning me on the counter, my feet couldn’t even touch the floor as he just mounted me then and there,” Mikey continued following Raph, chasing him around the couch until coming to a stop, sitting himself down on the arm of the couch and spreading his legs. “Right here,” he said, spreading his slit and Raph lowered his eyes, swallowing hard as he saw the physical change in Mikey for the first time. 

“They both had their way with me all morning, but you know what?” Mikey kept smiling, a finger toying with himself slowly. 

“What?” Raph asked, his voice low and rough, eyes transfixed by that finger as it slipped into Mikey’s slit. 

“All I could think about today was you, Donnie’s cock is so long, it pushes right up inside me,” Mikey moved his free hand, trailing it up his leg, then to his stomach, drawing small circles. “I can feel it, right up in here,” he said. “I can feel everything when he fills me,” Mikey moaned, tilting her head back as she moved her finger in deeper, toying with her insides. 

Raph’s nostrils flared, his tail stiff as his cock threatened to drop down. And it was only pure stubbornness that he managed to hold himself back. 

“Leo is different, not as long, not thick, but he’s hard, and eager,” Mikey continued with her explanation. “The pleasure of having him comes from how he moves, it’s graceful, and determined,” 

Raph took a deep breath, letting it out slowly, he forced himself to narrow his eyes. “And what does any of this have to do with me?” He said. 

“Haven’t you guessed yet, Raphie?” Mikey asked, spreading his legs wider, pushing his finger deeper, chirping as he must have hit something inside him that felt good. “I want your cock, I want to feel it, is it long like Donnie’s? Is it hard like Leo’s?” Mikey breathed out, his eyes trailing down as Raph lost the battle, his own cock dropping down, and Mikey licked his lips. “Or is it thick, thick enough for me to feel every inch of it as it stretches me open,”

Mikey slid from the arm of the couch, lifting his tail as he leaned over, spreading his legs, he braced himself over the arm of the couch, tilting his head to look at Raph. “Let me feel it, Raph,” 

Raph’s body was moving before his brain even registered what was happening, he had known at the beginning of the week that things were likely to end up like this, he wasted no time in grabbing Mikey’s hips with one hand, his cock with the other he tried to line it up with Mikey’s hole. 

Thrusting his hips forward, Raph growled as his cock pressed against Mikey, before slipping down and missing, pushing between her thighs he breathed out, pulling back he tried again, forcing himself to move slower, he guided his cock to her cloaca again, rubbing the head against it he felt Mikey shudder under him. 

Mikey pressed back and Raph practically howled as the head of his cock dipped into that warm slick cavern. Growling, a low and animalistic sound, Raph plunged his thick cock deep into Mikey with one swift thrust. The smaller turtle’s voice was muffled in the couch cushion, Raph only faltered slightly, a voice in the back of his mind had him looking down at the pinned turtle, needing to make sure he hadn’t hurt him with his abrupt penetration. 

Mikey turned his head to the side, his hands fisted in the couch cushion, cheeks flushed, eyes watering, and mouth open. He didn’t say anything, but Raph met his eyes and knew any more hesitation on his part wasn’t needed, Mikey wanted this, Mikey needed this, and Raph was going to give it to him. 

Hands gripping Mikey’s hips tightly he shifted him before pulling out and thrusting back in. Mikey’s scream was just as loud as before, and this time, Raph didn’t stop, pulling out and jabbing his hips forward again, grunting as his pelvice met Mikey’s ass again and again, driving his cock into him at a brutal pace. 

He’d waited for this, had wanted this for days, had convinced himself that his hand was good enough, and now, feeling those walls grip every inch of him, Raph knew he’d only been fooling himself. There was no way he would have been able to resist this for much longer, and now that he was buried inside Mikey, he knew he never wanted to stop. 

Mikey did his best to try and push himself up and back, wanting to contribute to the movements, but Raph was determined to keep full control of the situation, pressing one hand firmly to Mikey’s shell, he kept him pinned there as he rutted into him. 

There was something so right, so perfect, about the way Raph was giving in, about how Raph couldn’t seem to get close enough, or deep enough. 

Mikey felt something shift, and turned his head once more to see that Raph had lifted one foot up and over the arm of the couch, and Mikey shuttered as Raph really was mounting him. 

She chirped, and Raph churred in response, leaning over him. Mikey felt the heat in his gut building quickly from the dominating way Raph was fucking him, and Mikey let it happen, tilting his head back as much as he could, he cried out as he suddenly came. 

Raph paused for a moment, a slow smirk spreading over his lips. “Ya really wanted my cock that much, didn’t ya?” Raph asked, pulling out slowly and jerking his hips forward to bury himself back inside the tight space. 

“Yes, oh, oh fuck, yes, Raph, I wanted it, I want it!” Mikey cried out, yelping when Raph grabbed his mask tails, pulling his head back and forcing him to hold it up. 

“The moan for me, scream for me,” Raph demanded. “Louder than ya did for Donnie or Leo,” he slammed his hips forward, the sound of skin slapping skin, as well as the lewd wet sounds of Raph’s cock penetrating her leaking hole had Mikey doing as he was told, crying out with each rough thrust, shuddering in pleasure as he could feel the wonderful heat building again so quickly. 

“Fuck, fuck,” Raph hissed, looking down as he watched his cock moving in and out of Mikey, he couldn’t remember why he had held off from doing this, why he had been so adamant about stopping Donnie and Leo from having Mikey. 

The thought of Leo and Donnie doing this to Mikey though, of their cocks thrusting in and out of their little brother, of their seed filling him, Raph’s hand gripped Mikey’s bandana tighter, jerking his head back harder, and he started moving faster. 

“AHH! Ah, oh, fff-ngh!” Mikey couldn't seem to make any coherent noises, and this only seemed to fuel Raph even more, had his chest puffing up in pride knowing that he’d managed to get that reaction from Mikey. 

“Mine,” Raph growled. “You’re mine,” He said and watched as Mikey tried to turn his head to look at him, confusion mixed with pleasure reflected in those baby blue eyes. “This,” Raph insisted, jabbing his hips forward hard and fast, seating his cock deep inside Mikey. “This is mine,” 

Mikey opened his mouth to say something, and Raph narrowed his eyes. “Agree with me, and I’ll give you what you want, what we both want,” Raph said and Mikey’s eyes widened, while Raph’s smirk did the same. “You want my seed, you want me to cum in you,” Raph said, his voice low, his hips never stopping. 

Mikey nodded his head weakly, opening his mouth to agree, but the only sound that came out was another chirp. 

“You want me to fill you,” Raph continued, moving his hand that had been gripping Mikey’s hip around, cupping his stomach. “I’ll give you that, I’ll fill you, I’ll make you pregnant,” 

Mikey let out a loud moan, his eyes flickering as he closed them, his insides clenched around Raph’s cock at the thought of it. 

“Say it,” Raph demanded. 

Mikey opened his mouth to do as he was told, but he was still having trouble forming the words, only moans and gasps were escaping him as Raph continued rutting into him, rocking him forward over the arm of the couch. It wasn’t until Raph slowed down, stilling with just the tip of his cock inside him that Mikey managed it. 

“...in me,” Mikey gasped out. “Cum… cum in me, Raph! Raph cum in me please! I need it, I… I’m yours, please, please, please!” 

“What do you want?” Raph said, his own hips shuddering as he held himself back from completion. 

“Fill me! Make me pregnant please! I want it!” Mikey sobbed and Raph slammed forward, letting go of Mikey’s mask as he leaned over him, pounding into him with reckless abandon. 

Mikey screamed, his fingers clawing at the couch cushions under them, his insides clenching and gripping at Raph, trying to hold him inside now that he knew what he wanted, now that Raph had put the idea in his mind. 

The heat in his gut suddenly released, washing over Raph’s cock, and that was Raph’s undoing as well, with a roar, he stilled inside Mikey, his cock pulsing as he shot his seed deep inside, filling him, his hand still gripping Mikey’s stomach. “Mine,” he growled out again, and Mikey could only weakly nod in agreement, because in that moment, he would have agreed to anything. 

END


End file.
